I recently gave two lectures about physics and computer science in my kids school (2018-02). The lecture covered simple physics experiments plus some software show and
self playing. The kids were very OK with it and - because this is hard for them to type and find internet adresses of those many scattered
web toy I made simple linking website, named it felp.pl and published. Enjoy! I would say these apps are for children at age 2-102.
Keep in mind, not all the apps here are mine - some of them I wrote by myself but to some of them I simply link there
Anyway, I will be happy to get some feedback on that and ideas what more to include here!